Transmission for engines



A. L. POWELL. mmsmsswn Fon ENGINES.

APPLICATION FILED DC. 8! |920.

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A. L. POWELL.

TRANSMISSION FOR ENGINES.

APPLICATION msu oec. 8. 1920.

Patented July 12, 1921.-

@wam-1 A. L. POWELL'. TRANSMISSION Foa memes.

APPLICAUON 'FILED DEC. 8p i920. n

Patentd July 12, 1921` 1o SHEETS-sneer s.

A. L. POWELL.

TRANSMISSION FOR ENGINES.

APPLlAlou man Deca, |920.

Patented July 12, 19.21.

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A. L. POWELL'. TRANSMISSION FOR ENGINES, APPLICATION FILED DEC. 8, i920. 1,384,335. Patented July 12, 1921 A. L. POWELL.

TANSMiSSIN FOR ENGNES.

APPLICATION FILED DEC-M1920. 1,384,335 Patented. 12,

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`A. WELL.v

TRANSMI ,L FOR ENGINES.

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l,384,335 Patented July 12, 1921.

I0 SHEETS-SHEET 9 lll llltll'l STATES PATENTl OFFICE.

AL'VAH L. PGYVELL, 0F MLES CTY, MGNTNAfASSIGNDR T0 THE A. L. POWELL PO'WERA CO., 0F MILES CTY, MQNTANA, A CGRPORATION.

'rnANsMrssroN ron ENGINES.

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application med :oem-.meer s,- 1.920.

To d 'whom/ may concern:

lBeit known that I, ANAH L. Powntn, citizen ol: the lUnited States. residing at lvlilesl City, in the county o't (luster and State of Montana, have invented certain new and useful Improvements in Transmission for Engines, of which. the following is a speci-V hcation.

My invention relates to improvements in tiret ansmitting rneml er of engines by which secure a'variation in the movement of the piston with reference to that ol the crank, that enables me to gain advantages in the operation of such engines that are impossible with the construction at present nsed. My improvement consists inthe introduction ot a lever, between the piston and crank rod,

that alters the piston vmovement with reference to that oit the. crank so that, while this piston may move,

vill travel only four. The lever to which l refer acts, therefore, as' a reducing agent with reference to the engine speed,.the addi* onal force developed in the longer stroke the piston enabling me to produce 'the sami power at a lower speed or" the crank. ln the majority of heat engines it is desirable to reach the theoretical power at a minimum speed. Certain very useful types of these engines are handicapped by the great number of revolutions necessary to develop the power for which they were designed. ln the explosion engine in particular, that` tie, those in which air and gaseous vapor are mired and ignited7 high speed is the rule. ln my invention l am able to reduce this, the additional cylinder space, and consequent :increase ott piston stroke., lengtheningl ythe interval of movement with reference to time, thas ellieeting ay slowing down of the en .ejine withmit reducing power.

ln all. engines intended for high duty this is desirable. Marine engines ot the explosion class furnish power to the driving shaft through systems of gearing that involve expense and greater wear and tear than is found with the direct connecting gear ot' reciprocatine team engines. wear is an e. itial defect in all such power machines. On 'the other hand, by using the additional working` area in the cylinder I am able to secure further expansion of the charge, with a ctmseqnent increase of thermal. eliicieney; or, ll may increase the volume of the charge and power ot' the engine at Specification of Letters Patent.

say, six inches, the crank This 'greater yPatented July 12, 1921.

Serial No. 429, 1G8.

the same time, securing,Y from it the working advantages of an engine of, say, six inch stroke, compressed, or concentrated, into a crank movement ot' four. thus raising the torque of the engine shaft. To go further, I may utilize this extra part of the stroke as a cooling means, as hereinafter to be described. ln engine design this piston relation to stroke effects a reduction of cylinder surface, with reference to crank power, of great importance to the designer, as' a minimum of radiation surface 'for a given horse power is made possible. i.,

Many modifications of the lever principle l employ are possible, but I have confined my description to aspecitic form, embraced in the drawings annexed, but I include in the views covered by the drawings some modifications ot' the main design, and some applications of my invention to standard types of engines. O'fthese drawings- Figure l is an elevation, partly in section, of the variable movement lever, showing it in connection with. acylinder and crank shaft.

Fig. 2 is the same at quarter stroke.

Fig. is the same at half stroke.

Fig. 4 is a sectional view of the lever mechanism.

Fin'. 5 shows, in section, the variation in' position of the connecting rod rack.

Fig. G is ay diagram of the intake, at full stroke.

Fig. 7 is an elevation ot the lever mechanism, showing piston at end of downstroke.

Fig. 8 is adiagrram to show that the leverage may be varied to secure any desired stroke.

Fig. 9 is a diagram of the power cycle, where the additional area ot the stroke is used Vfor a cooling and retarding means.

Fig. l() is another diagram, to accompany Fig'. 9.

Fig. ll is a diagram ot a two cycle engine, embracing my variable stroke.

Fig. 12 is an elevation, showing a modification in the arrangementoi the crank shaft with reference to the engine cylinder.

, are, Fig. 18. l

modification in the construction of the lever mechanism.

Fig. 17 shows the parts given in in another part of the stroke. Fig. 18 is the same, at' end. of stroke.

Fig. 19 is a longitudinal section of the same, the parts being shown in elevation.

Fig. 20 is a transverse section on the line Fig. 16

Fig. 21 shows a modiiication of the construction given in Figs. 16 to 20, inclusive.

Fig. 22 is a longitudinal section of the` piston rod shown in Fig. 21..

Fig. 23 is a transverse section of the saine. -F ig. 24 shows an application ot my in-` Aventioii to awalking beam steam engine.

Fig. 25 represents my lever mechanism attachedto the driving gear 'of a steam loco` 'motive'. j 2,0

tons of a two cycle engine ot the double acc Fig. 426. represents the. cylinder and pis-- tion class, to indicate that my improvement may be applied to sucli engines, deriving the advantage of power on both sides of stroke. Fig. 27 is a further modification of the yoke-supported rack form ofmy improvement.

Fig. 28 is a lsectional View, on the dotted 4 lline (Fig. 27) `shown with arrows.

ing the relative proportions of steam cylinders as affected by the long stroke ot' my. transmission member. i

Figs. 29 and 30 are diagrammatic, shown the piston A eta gas engine transmits motion through the piston rods, or links, A1, Al,A hung onapin, A2, that passes through the piston walls.v These links are looselyheld` on the pin by means off the bolt shown, and a bushing, 3, is employed to allow for wear. The links A1, A1, conneet with crank levers, B, B,'by means oi pins shown at B1. The crank levers, B, B,

are'attached to a pin, B2, suitably supported in the engine `frame.. On the vsame pin there is a segmental pinion, B3; this pinion, and the crank levers B, B, being keyed to the pinBz. The segmental pinion B3 engages a' rack, B4,.that forms pa'rt of a connecting rod, B5. The 'connecting rod is attached to the shaft crank B, by, a 'wrist-pin B7, the construction beingi conventional. On the pinB2 there are also swung two arms, B8,

vwhich form a support for a slide bearin in which the connecting rod` B5 moves. he arms 138,138 are loosely yhung on the pin VB2 in order to allow free movementwith reference to the motion of thev connecting rod, B5.

To give proper support tothe rod B5 the` arms, B8, B areprovided with a tongued slidiig surface, B13", held in position by a cap, 9and the tap bolts,'B1, B1". Proper wearing surfaces o n the rod B5 are provided I, at IB12, a' free sliding Igroove for said rod being thus furnished. sectional view of this construction is A'given ,ini Fig/ 4f.

A, from which it derives its motion.

Under the conditions described it is evident that on the outstroke ot the piston the lever crank B will swing in an are downward, rotating the pin B2, andcausingl the segmental pinion totransmit movement to the toothed connecting rod, B5. This rod will move the shaft crank, B, thus transmitting the vpower developed in the engine cylinder to the engine shaft. The connecting rod will move in the guiding and retaining means provided bythe capped arms, B8, BS, and, as the V piston moves forward and backward, the reciprocating'motion of the said piston will-.be converted into a movement of rotation at the crank circle. It will he noted however. that the crank B is at-` tached to the piston links .A1-A1 a-t a point corresponding with the length of said cra-nk,

ion B3. Under these conditions the stroke` oi' tliecrank B will be four inches.

The *force developed in a long stroke is. in this way, concentrated in the shorter stroke of a suitably connected crank, the effect be ing a leverage that compresses the power et a six inch working piston stroke into a four inchV working crank stroke. I thus gear down piston movement to secure power concentration, the leverage means employed being composed of niembersinhcrent in the transmitting means. These means are of a practical and effective form, adapted to long weai, and are simple with reference to structure.

It is evident that the duration of pistonstroke is a variable quantity, 'for vas the length increases the 'time ot travel extends, other factors being equal. The speed of shaft rotation will therefore be less, in an engineof long stroke than in one that is shorter, diameters, volume, compression and-back pressure remaining the same, but the transmitted power 'will correspond to that ofthe energy developed during the piston stroke. Under these conof stroke I secure by the use of 'a leverV system between power cylinder and crank shaft, effect a reduction of speed that is of Vgreat importance in engine design w h ile, at

in' im engine cylinder y ditions I can, by reason of the extra length i the same time, retaining the power of a cyiindei' of given diameter. It is obviousthat.v

theproporton of excess 'strokeover that of Eli? the engine crank may be varied by altering the distance of the pin B1 and the pitch circle of the pinion B3.

ln an engine ot this type the additional piston stroke may be utilized for other purposes than that of thc direct development of power, but securing thereby advantages equivalent thereto. in an engine ot' relatively small diameter the piston stroke is `twelve inches. The expansive force ot' the charge will exert pressure against the piston for a distance corresponding to the tall oi temperature ot the expanding charge, and this will insure power development Ito a point approximately beyond the middle of the stroke; that is, for a distance greater than six inches. The piston will, thereafter, travel by themomentum ot' the crank mechanism, absorbing power from it and acting as a braking, or retarding, means, lowering en.- gine speed. At a point in the long stroke a condition of partial vacuum will develop in the cylinder, which will tend to lower the temperature of the spent gases and, further, lead to an absorption o't heat from the cylinder and piston walls. At the end of stroke, when the exhaust valve opens, atmospheric pressure will be restored in the cylinder, and the incomingv air will retain the heat that has been absorbed by the burnt gases from the engine walls. This heat will pass through the exhaust valve with the dead charge. 1n an engine of this kind vpart of the stroke of' the piston would develop power, while, during the remainder, it would act as a pump for removing heat. lVliile the action was taking place vthis would involve a loss of power, but the cooling effect on walls and piston would raise the eliiciency of the engine as a whole. The point of exhaust could also be extended, permitting the expansion of the power charge to an extreme point. In F ig. 11 l show a. diagram of' the operation of my differential principleto a two cycle engine. In Fig. 5 tlie'positions ot' the rack and the longitudinal positions of the piston rods Al--Al are vshown at extreme points of stroke. Figs. 1, 2, 3 and 't' show the positions ol? the variable stroke members through one revolution.

ln Fig. 12 Gl show a novel arrangement of my transmitting members, by means ot which l am able to throw the center of the crank shaft beyond the center line of thev piston,r without altering'movement or loweriii/stead, a guide in the nature of a yoke, C,

arranged to press against a loose collar on the pin B2. As the segmental pinion B3 tends to Aforce the rack away the surface of liet it be assumed that (l, pressing against the colla'r on B2, holds it in proper alinemcnt with reference to the movement ot the connecting rod B5. In `this,construction l employ, preferably, two racks and two segmental pinions` the guide U moving between,"'as shown in the vertical elevation, Figs. l) and 20, the latter a sectional view. The guide C is attached to the connecting rod B by means of tap bolts, as shown at C1, C1.

ln Figs-21, 22, 23,1 show a further mod itication of my transmitting members. In this, l follow the construction given in Figs. 16, 17 and 18` but in addition thereto l use grooves, l), forming part of the piston rod l 1, and make this rod rigid',in the position shown. 'lhe reciprocating action of the iiston causes this rod to press on the rollers ly and gives motion to the lever cranks B B.

In Fig. 25 l show an application of my invention to the steam engine of a locomotive. Figs. 29 and 30 are diagrams indicating the variation of cylinder proportions required to adapt my invention to such an engine. As the travel of the piston exceeds that of the crank, I lengthen the cylinder in order to be able to effect a proper cut-oil1 ot' the steam. By reducing 4the diameter of, the steam cylinder and increasing its length l maintain the same area by volume.

It is evident that many forms ot' my invention may be made, and that the proportions of leverage to stroke can be changed to meet various conditions. l donot limit myself to the exact forms of the invention shown in thisapplication.

Vhat ,I claim to be novel, and ask vto have protected by Letters Patent, is-

1. In. a transmission member, the combination of an engine, a piston in said engine, a lever pivoted in relation toV said piston, a pinion having a pitch diameter dilferent from the length of said lever, a rack engaging said pinion, a pivoted movable guide for holding said rack in engagement with said lever, and a power shaft rotatable by the movement of said rack,.`substantially as described.

2. n a transmission member, the combination of an engine, a pistonin said engine,

ilo

a lever pivoted in relation to said engine lever, a pinion having a pitch diameter different from the length of said lever, means for moving the lever and pinion synchronously. a rack engaging said pinion, a pivoted. slidable guide for holding the rack in engagement 'with said pinion, and a power shaft rotatable by the movement of said rack, substantially as described. v

3.111 a'ti'ansmission member, the combination` of an engine, a piston in said engine, a lever pivoted in relation to said engine, a rod extending from said piston, means vfor connecting said rod to said piston, a pinj rack, and a power shaft rotatable by the ac-` tion of said crank, substantially as Ide;

scribed. f

4. In a power transmission member, the.

combination of an engine, a piston` in 'said engine,`a rod gi'ooved at its lower end and rigidly attached to said piston, a lever .pivoted in'relation 'to said piston andv rod, a

roller on said lever fittin in the groove of.

said rod, a pin supporte in frame of said engine, a pinion pivotedon said pin, a rackI engaging the teeth of said pinion, means for .holding said rack inlengagement with said pinion, a crank connecting rod forming part of said rack, and a crank that imparts the motion of said rack to a power shaft, substantially as described.

In testimony whereof I aiix my si nature.

ALVAH L. PO ELL.. 

